The present invention relates to devices used for the detection of magnetic fields and more particularly to an improved system wherein optical fibers are used to transmit polarized light for measuring the magnitude and direction of a magnetic field.
In the detection and measurement of a magnetic field environment, various field-responsive sensors have been employed in compasses to detect field direction and in magnetometers to measure field strength. Although these magnetic field sensors, useful for navigational purposes as well as underwater and subsurface exploration, have generally been accurate regarding the true nature of the magnetic field vector in a particular area, greater sensitivity and reliability is being required, particularly of those sensors employed in current airborne applications.
While various magnetic field sensors have been developed for determining the direction of the magnetic field in an area and for detecting the associated field strength, they have not been entirely effective in providing the high degree of accuracy and reliability now being demanded. Specifically, the continued use of and reliance on electrical sensing elements subject many existing magnetic field sensors to errors from self-generated inteference. In addition the inclusion of moving parts in numerous field-responsive sensors subject them to wear and the associated problems caused thereby. Finally, existing field sensor systems have evidenced an overall need for increased sensitivity in order to improve the accuracy of measurement of relatively small magnetic fields.